Annual report pursuant to Section 13 and 15(d)

Income Taxes - Reconciliation of Statutory Tax Rates to Effective Tax Rates (Detail)

v3.20.4
Income Taxes - Reconciliation of Statutory Tax Rates to Effective Tax Rates (Detail)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract]      
Federal income taxes at statutory rate 21.00% 21.00% 21.00%
Impact of stock compensation (2.40%) 0.10% 0.00%
Non-deductible executive compensation (0.10%) (0.70%) (0.70%)
Capitalized research 0.00% 0.00% 7.80%
Other 0.30% (0.20%) (0.60%)
Change in valuation allowance (18.80%) (20.20%) (27.50%)
Effective tax rate 0.00% 0.00% 0.00%